Management of opioid analgesic overdose

Recent Overdose Experiences in a Community Sample of Military Veterans Who Use Opioids

Rising rates of overdose mortality underscore the importance of understanding and preventing overdose. We developed a seven-item scale for the assessment of nonfatal opioid-related overdose experiences, adding items on others' perceptions of whether the participant had overdosed and whether an intervention was attempted to frequently used criteria. We administered the scale to 240 primarily male and minority veterans, recruited using venue-based and chain-referral sampling, who separated from the military post-9/11 and reported current opioid use. The items were internally consistent, and correlated well with overdose risk behaviors (r = .13-.45). The new scale detected overdose events in a significantly higher proportion of participants (36.5%) than that using either self-report criterion (18.2%) or difficulty breathing and losing consciousness criteria (23.8%). These experiences or perceptions should be investigated to inform and better tailor the development of more effective overdose prevention and response programs.

Substance Use, Intoxication, and Withdrawal in the Critical Care Setting

Substance use is common among individuals admitted to the critical care setting and may complicate treatment of underlying disorders. Management issues include the effects of intoxication as well as the risk posed by substance-withdrawal syndromes in patients being treated for critical illness. This article reviews the epidemiology of substance use in this population and the identification and treatment of common intoxication and withdrawal syndromes. The authors stress the importance of long-term planning as part of the overall treatment protocol beyond the acute presentation.

Naloxone administration for suspected opioid overdose: An expanded scope of practice by a basic life support collegiate-based emergency medical services agency

Opioid abuse is a growing and significant public health concern in the United States. Naloxone is an opioid antagonist that can rapidly reverse the respiratory depression associated with opioid toxicity. Georgetown University's collegiate-based emergency medical services (EMS) agency recently adopted a protocol, allowing providers to administer intranasal naloxone for patients with suspected opioid overdose. While normally not within the scope of practice of basic life support prehospital agencies, the recognition of an increasing epidemic of opioid abuse has led many states, including the District of Columbia, to expand access to naloxone for prehospital providers of all levels of training. In particular, intranasal naloxone is a method of administering this medication that potentially avoids needlestick injuries among EMS providers. Universities with collegiate-based EMS agencies are well positioned to provide life-saving treatments for patients acutely ill from opioid overdose.

Designer drugs: Review and implications for emergency management

In the past 10 years, "designer drugs" such as synthetic cannabinoids and cathinones have emerged and come into widespread use, resulting in more overdose cases involving these new drugs in the United States. Emergency departments regularly treat a diverse array of drug intoxications, and providers must be cognizant of novel drugs of abuse and the associated clinical presentations in order to provide the most appropriate care. This review aims to describe the epidemiology, mechanism of action, clinical presentation, and treatment of intoxication for both the common and newest drugs of abuse.

Buprenorphine-Related Complications in Elderly Hospitalised Patients: A Case Series

We report a case series of buprenorphine-related respiratory and neurological depression in opioid-naïve elderly hospitalised patients who received buprenorphine for acute pain management at our institution over a 24-month period. All six patients had risk factors for respiratory depression such as advanced age, concurrent comorbidities, or the ingestion of other potential central nervous system depressants. All patients required escalation of management with additional monitoring, with some transferred to a high dependency or intensive care unit. Five patients had attempted naloxone reversal with varying results. Our cases highlight the fact that while buprenorphine has been demonstrated to have a ceiling effect in relation to respiratory depression in healthy volunteers, it remains an important side-effect and may result in significant respiratory depression in patients with reduced respiratory or neurological reserve. Difficulties with buprenorphine's reversal using naloxone are described. We recommend additional caution when considering buprenorphine for acute pain management in elderly opioid-naïve patients, especially if they have comorbidities or are taking other central nervous system depressants. When buprenorphine is used in patients with risk factors, we recommend additional monitoring and education about potential adverse respiratory effects and their management.

Effects of naloxone distribution alone or in combination with addiction treatment with or without pre-exposure prophylaxis for HIV prevention in people who inject drugs: a cost-effectiveness modelling study

BACKGROUND

In the USA, an epidemic of opioid overdose deaths is occurring, many of which are from heroin. Combining naloxone distribution with linkage to addiction treatment or pre-exposure prophylaxis (PrEP) for HIV prevention through syringe service programmes has the potential to save lives and be cost-effective. We estimated the outcomes and cost-effectiveness of five alternative strategies: no additional intervention, naloxone distribution, naloxone distribution plus linkage to addiction treatment, naloxone distribution plus PrEP, and naloxone distribution plus linkage to addiction treatment and PrEP.

METHODS

We developed a decision analytical Markov model to simulate opioid overdose, HIV incidence, overdose-related deaths, and HIV-related deaths in people who inject drugs in Connecticut, USA. Model input parameters were derived from published sources. We compared each strategy with no intervention, as well as simultaneously considering all strategies. Sensitivity analysis was done for all variables. Linkage to addiction treatment was referral to an opioid treatment programme for methadone. Endpoints were survival, life expectancy, quality-adjusted life-years (QALYs), number and percentage of overdose deaths averted, number of HIV-related deaths averted, total costs (in 2015 US$) associated with each strategy, and incremental cost per QALY gained.

FINDINGS

In the base-case analysis, compared with no additional intervention, the naloxone distribution strategy yielded an incremental cost-effectiveness ratio (ICER) of $323 per QALY, and naloxone distribution plus linkage to addiction treatment was cost saving compared with no additional intervention (greater effectiveness and less expensive). The most efficient strategies (ie, those conferring the greatest health benefit for a particular budget) were naloxone distribution combined with linkage to addiction treatment (cost saving), and naloxone distribution combined with PrEP and linkage to addiction treatment (ICER $95 337 per QALY) at a willingness-to-pay threshold of $100 000. In probabilistic sensitivity analysis, the combination of naloxone distribution, PrEP, and linkage to addiction treatment was the optimal strategy in 37% of iterations and the combination of naloxone distribution and linkage to addiction treatment was the optimal strategy in 34% of iterations.

INTERPRETATION

Naloxone distribution through syringe service programmes is cost-effective compared with syringe distribution alone, but when combined with linkage to addiction treatment is cost saving compared with no additional services. A strategy that combines naloxone distribution, PrEP, and linkage to addiction treatment results in greater health benefits in people who inject drugs and is also cost-effective.

FUNDING

State of Connecticut Department of Public Health and the National Institute of Mental Health.

A review: Fentanyl and non-pharmaceutical fentanyls

BACKGROUND

Fentanyl and non-pharmaceutical fentanyls (NPFs) have been responsible for numerous outbreaks of overdoses all over the United States since the 1970s. However, there has been a growing concern in recent years that NPFs are contributing to an alarming rise in the number of opioid-related overdoses.

METHODS

The authors conducted a narrative review of the published and grey literature on fentanyl and NPFs in PubMed, Google Scholar, and Google using the following search terms: "fentanyl", "non-pharmaceutical fentanyl", "fentanyl analogs", "fentanyl laced heroin" and "fentanyl overdose". References from relevant publications and grey literature were also reviewed to identify additional citations for inclusion.

RESULTS

The article reviews the emergence and misuse of fentanyl and NPFs, their clinical pharmacology, and the clinical management and prevention of fentanyl-related overdoses.

CONCLUSIONS

Fentanyl and NPFs may be contributing to the recent rise in overdose deaths in the United States. There is an urgent need to educate clinicians, researchers, and patients about this public health threat.

Pharmacokinetics of a new, nasal formulation of naloxone

PURPOSE

Nasal naloxone is wanted for bystander administration in opioid overdose and as a needle-free alternative for emergency medical personnel. Epidemiologic studies have indicated a therapeutic effect of bystander administration of low-concentration/high-volume formulations. The objective for this study was to describe the nasal pharmacokinetics of a new high-concentration/low-volume nasal formulation of naloxone.

METHODS

This was an open, randomized triple crossover trial in healthy, human volunteers (n = 12) where two doses of nasal naloxone (0.8 and 1.6 mg) and one intravenous dose (1.0 mg) were compared. Fifteen serum samples were collected before and until 6 h after naloxone administration. Quantification of naloxone was performed by a validated liquid chromatography-tandem mass spectrometry method.

RESULTS

Bioavailability was 0.54 (0.45-0.63) for the 0.8 mg and 0.52 (0.37-0.67) for the 1.6 mg nasal naloxone formulation. Maximum concentration levels (C _max) were 1.45 ng/ml (1.07-1.84) for 0.8 mg and 2.57 ng/ml (1.49-3.66) for the 1.6 mg. Time to maximum concentrations (T _max) were reached at 17.9 min (11.4-24.5) and 18.6 min (14.4-22.9) for the 0.8 mg and the 1.6 mg doses, respectively.

CONCLUSION

This nasal naloxone formulation had a rapid, systemic uptake and higher bioavailability than naloxone formulations not designed for IN use. This indicates that an optimized high-concentration/low-volume nasal spray formulation may deliver a therapeutic dose. The 1.6 mg nasal dose provided serum concentrations that surpassed those of 1.0 mg IV after 15-20 min and stayed above for the rest of the study period.

Barriers to implementation of opioid overdose prevention programs in Ohio

BACKGROUND

Nationally, overdose fatalities have reached epidemic proportions. Ohio has one of the highest overdose death rates in the country, as well as high rates of prescription opioid trafficking.

METHODS

A cross-sectional self-report survey of opioid overdose prevention programs (OOPPs) in Ohio was conducted between August and October 2014 to characterize programs and ascertain barriers to successful implementation. A 91% response rate was achieved with 18 programs participating in the study.

RESULTS

The first Ohio OOPP opened in August 2012, a second program opened in 2013, and the remaining programs began in 2014. All of the programs distribute nasal naloxone and provide overdose prevention education, and 89% (n = 16) provide overdose kits for free. Six OOPPs are funded by the Ohio Department of Health, 3 programs are funded by a local health foundation, and several other public and private funding sources were reported. The OOPPs have funding to distribute a combined total of 8,670 overdose kits and had distributed 1998 kits by October 2014. The OOPPs reported 149 overdose reversals. Fifteen programs (83%) reported implementation barriers that were categorized as stigma-, cost-, staffing-, legal, regulatory, and client-related problems. Legislative changes aimed at removing some of the obstacles to distribution and lay administration of naloxone have recently been enacted in Ohio.

CONCLUSIONS

OOPPs have rapidly expanded in Ohio during the past 3 years. Although recent legislative changes have addressed some of the reported implementation barriers, stigma and the cost of naloxone remain significant problems.

Toward a Blood-Borne Biomarker of Chronic Hypoxemia: Red Cell Distribution Width and Respiratory Disease

Hypoxemia (systemic oxygen desaturation) marks the presence, risk, and progression of many diseases. Episodic or nocturnal hypoxemia can be challenging to detect and quantify. A sensitive, specific, and convenient marker of recent oxygen desaturation represents an unmet medical need. Observations of acclimatization to high altitude in humans and animals reveals several proteosomic, ventilatory, and hematological responses to low oxygen tension. Of these, increased red cell distribution width (RDW) appears to have the longest persistence. Literature review and analyses of a 2M patient database across the full disease pathome revealed that increased RDW is predictive of poor outcome for certain diseases including many if not all hypoxigenic conditions. Comprehensive review of diseases impacting the respiratory axis show many are associated with increased RDW and no apparent counterexamples. The mechanism linking RDW to outcome is unknown. Conjectural roles for iron deficiency, inflammation, and oxidative stress have not been born out experimentally. Sports-doping studies show that erythropoietin (EPO) injection can induce formation of unusually large red blood cells (RBC) in sufficient numbers to increase RDW. Because endogenous EPO responds strongly to hypoxemia, this molecule could potentially mediate a long-lived RDW response to low oxygenation. RDW may be a guidepost signaling that unexploited information is embedded in subtle RBC variation. Applying modern techniques of measurement and analysis to certain RBC characteristics may yield a more specific and sensitive marker of chronic pulmonary and circulatory diseases, sleep apnea, and opioid inhibition of breathing.

Reversal of Opioid-Induced Ventilatory Depression Using Low-Dose Naloxone (0.04 mg): a Case Series

INTRODUCTION

Naloxone is commonly administered in emergency department (ED) to reverse opioid intoxication. Several naloxone dose recommendations exist for acute management of opioid intoxication based on limited published clinical data. A case series of ED patients with opioid-induced ventilatory depression that was reversed using a low-dose naloxone (0.04 mg with titration) is presented.

METHODS

ED patients with opioid-induced ventilatory depression requiring naloxone administration were identified through medical toxicology consultation. Retrospective review of medical records was performed. Collected data included history, and pre- and post-naloxone data, including respiratory rate (RR), pulse oximetry (pulse ox), end-tidal CO2 level (ET-CO2), and Richmond Agitation Sedation Scale (RASS).

RESULTS

Fifteen ED patients with moderate to severe opioid-induced ventilatory depression (median RR, 6 breaths/min) who were managed using low-dose naloxone strategy were identified. Twelve of 15 patients reported ingestion of methadone (range, 30 to 180 mg). The median naloxone dose of 0.08 mg (range, 0.04 to 0.12 mg) reversed opioid-induced ventilatory and CNS depression. Two patients experienced acute opioid withdrawal after receiving 0.08 mg.

CONCLUSION

ED patients with moderate to severe opioid-induced ventilatory depression can be reversed using 0.04 mg IV naloxone with appropriate dose titration.

Efficacy of naloxone in reducing postictal central respiratory dysfunction in patients with epilepsy: study protocol for a double-blind, randomized, placebo-controlled trial

Background

Generalized tonic-clonic seizures (GTCSs) are the main risk factor for sudden unexpected death in epilepsy (SUDEP). Experimental and clinical data strongly suggest that the majority of SUDEP results from a postictal respiratory dysfunction progressing to terminal apnea. Postictal apnea could partly derive from a seizure-induced massive release of endogenous opioids. The main objective of this study is to evaluate the efficacy of an opioid antagonist, naloxone, administered in the immediate aftermath of a GTCS, in reducing the severity of the postictal central respiratory dysfunction.

Methods/design

The Efficacy of Naloxone in Reducing Postictal Central Respiratory Dysfunction in Patients with Epilepsy (ENALEPSY) study is a multicenter, double-blind, randomized, placebo-controlled trial conducted in patients with drug-resistant focal epilepsy who are undergoing long-term video-electroencephalogram (EEG) monitoring (LTM) in an epilepsy monitoring unit (EMU). We plan to randomize 166 patients (1:1) to receive intravenous naloxone (0.4 mg) or placebo in the immediate aftermath of a GTCS. Because inclusion in the study needs to take place prior to the occurrence of the GTCS, and because such occurrence is observed in about one-fourth of patients undergoing LTM, we plan to include a maximum of 700 patients upon admission in the EMU. The primary endpoint will be the proportion of patients whose oxygen saturation is <90 % between 1 and 3 min after the end of a GTCS. Secondary outcomes will include the following: the proportion of patients who show postictal apnea, the occurrence and duration of postictal generalized EEG suppression, the total duration of the postictal coma, postictal pain, and the number of patients who have a second GTCS within 120 min after the intravenous injection.

Discussion

The demonstration of naloxone’s efficacy on the severity of postictal hypoxemia will have two primary consequences. First, naloxone would be the first and only therapeutic approach that could be delivered immediately to reverse postictal apnea. Second, demonstration that an opioid antagonist can effectively reduce postictal apnea would pave the way for an assessment of a preventive therapy for SUDEP targeting the same pathophysiological pathway using oral administration of naltrexone.

Trial registration

ClinicalTrials.gov identifier: NCT02332447. Registered on 5 January 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1653-1) contains supplementary material, which is available to authorized users.

Something for pain: Responsible opioid use in emergency medicine

The United States is currently experiencing a public health crisis of opioid addiction, which has its genesis in an industry marketing effort that successfully encouraged clinicians to prescribe opioids liberally, and asserted the safety of prescribing opioids for chronic non-cancer pain, despite a preponderance of evidence demonstrating the risks of dependence and misuse. The resulting rise in opioid use has pushed drug overdose deaths in front of motor vehicle collisions to become the leading cause of accidental death in the country. Emergency providers frequently treat patients for complications of opioid abuse, and also manage patients with acute and chronic pain, for which opioids are routinely prescribed. Emergency providers are therefore well positioned to both prevent new cases of opioid misuse and initiate appropriate treatment of existing opioid addicts. In opioid-naive patients, this is accomplished by a careful consideration of the likelihood of benefit and harm of an opioid prescription for acute pain. If opioids are prescribed, the chance of harm is reduced by matching the number of pills prescribed to the expected duration of pain and selecting an opioid preparation with low abuse liability. Patients who present to acute care with exacerbations of chronic pain or painful conditions associated with opioid misuse are best managed by treating symptoms with opioid alternatives and encouraging treatment for opioid addiction.

G-protein-gated Inwardly Rectifying Potassium Channels Modulate Respiratory Depression by Opioids

BACKGROUND

Drugs acting on μ-opioid receptors (MORs) are widely used as analgesics but present side effects including life-threatening respiratory depression. MORs are G-protein-coupled receptors inhibiting neuronal activity through calcium channels, adenylyl cyclase, and/or G-protein-gated inwardly rectifying potassium (GIRK) channels. The pathways underlying MOR-dependent inhibition of rhythmic breathing are unknown.

METHODS

By using a combination of genetic, pharmacological, and physiological tools in rodents in vivo, the authors aimed to identify the role of GIRK channels in MOR-mediated inhibition of respiratory circuits.

RESULTS

GIRK channels were expressed in the ventrolateral medulla, a neuronal population regulating rhythmic breathing, and GIRK channel activation with flupirtine reduced respiratory rate in rats (percentage of baseline rate in mean ± SD: 79.4 ± 7.4%, n = 7), wild-type mice (82.6 ± 3.8%, n = 3), but not in mice lacking the GIRK2 subunit, an integral subunit of neuronal GIRK channels (GIRK2, 101.0 ± 1.9%, n = 3). Application of the MOR agonist [D-Ala, N-MePhe, Gly-ol]-enkephalin (DAMGO) to the ventrolateral medulla depressed respiratory rate, an effect partially reversed by the GIRK channel blocker Tertiapin-Q (baseline: 42.1 ± 7.4 breath/min, DAMGO: 26.1 ± 13.4 breath/min, Tertiapin-Q + DAMGO: 33.9 ± 9.8 breath/min, n = 4). Importantly, DAMGO applied to the ventrolateral medulla failed to reduce rhythmic breathing in GIRK2 mice (percentage of baseline rate: 103.2 ± 12.1%, n = 4), whereas it considerably reduced rate in wild-type mice (62.5 ± 17.7% of baseline, n = 4). Respiratory rate depression by systemic injection of the opioid analgesic fentanyl was markedly reduced in GIRK2 (percentage of baseline: 12.8 ± 15.8%, n = 5) compared with wild-type mice (72.9 ± 27.3%).

CONCLUSIONS

Overall, these results identify that GIRK channels contribute to respiratory inhibition by MOR, an essential step toward understanding respiratory depression by opioids.

Opioid abuse in the United States and Department of Health and Human Services actions to address opioid-drug-related overdoses and deaths

On March 26, 2015, the Office of the Assistant Secretary for Planning and Evaluation of the U.S. Department of Health and Human Services (HSS) published an online Issue Brief that addresses opioid abuse in the United States and (HHS) actions to address opioid-drug-related overdoses and deaths. This report, which contains the full content of the Issue Brief, is adapted from that document.

Harm Reduction: Front Line Public Health

Drug use is a public health problem associated with high mortality and morbidity, and is often accompanied by suboptimal engagement in health care. Harm reduction is a pragmatic public health approach encompassing all goals of public health: improving health, social well-being, and quality of life. Harm reduction prioritizes improving the lives of people who use drugs in partnership with those served without a narrow focus on abstinence from drugs. Evidence has shown that harm reduction oriented practice can reduce transmission of blood-borne illnesses, and other injection related infections, as well as preventing fatal overdose.

Outpatient treatment of acute poisoning by substances of abuse: a prospective observational cohort study

Background

Procedures for the clinical assessment of acute poisoning by substances of abuse should identify patients in need of hospital admission and avoid hazardous discharges, while keeping the observation time short. We assess the safety of a systematic procedure developed at the Oslo Accident and Emergency Outpatient Clinic (OAEOC).

Methods

All patients 12 years and older treated for acute poisoning by substances of abuse at the OAEOC were included consecutively from October 2011 to September 2012. Data were collected on pre-set registration forms. Information on re-presentations to health services nation-wide during the first week following discharge was retrieved from the Norwegian Patient Register and from local electronic medical records. Information on fatalities was obtained from the Norwegian Cause of Death Registry.

Results

There were 2343 cases of acute poisoning by substances of abuse. The main toxic agent was ethanol in 1291 (55 %) cases, opioids in 539 (23 %), benzodiazepines in 194 (8 %), central stimulants in 132 (6 %), and gamma-hydroxybutyrate (GHB) in 105 (4 %). Median observation time was four hours. The patient was hospitalised in 391 (17 %) cases. Two patients died during the first week following discharge, both from a new opioid poisoning. Among 1952 discharges, 375 (19 %) patients re-presented at the OAEOC or a hospital within a week; 13 (0.7 %) with a diagnosis missed at the index episode, 169 (9 %) with a new poisoning, 31 (2 %) for follow-up of concomitant conditions diagnosed at index, and 162 (8 %) for unrelated events. Among the patients with missed diagnoses, five needed further treatment for the same poisoning episode, two were admitted with psychosis, one had hemorrhagic gastritis, another had fractures in need of surgery and four had minor injuries.

Conclusion

The procedure in use at the OAEOC can be considered safe and could be implemented elsewhere. The high re-presentation rate calls for better follow-up.

Clinical outcomes of cardiac arrest patients according to opioid use history

PURPOSE

Opioid analgesics are potent respiratory depressants. The purpose of this study was to describe the effects of opioids administered within 24hours before cardiac arrest on clinical outcomes.

MATERIALS AND METHODS

We retrospectively collected the cardiac arrest data of noncancer patients who were admitted to the general ward of Asan Medical Center from January 2008 to August 2012. We investigated the proportion of these patients who received opioids within 24hours of a cardiac arrest event, as well as the cardiac arrest characteristics, survival rates, and opioid administration patterns.

RESULTS

Of the 193 patients identified, 58 (30%) had been administered opioids within the previous 24hours (the opioid group), whereas the remaining 135 (70%) had not been administered opioids (the nonopioid group). The survival rate did not differ significantly between these 2 groups. In the opioid group, as-needed opioid administration was associated with a lower 24-hour survival rate than regular opioid administration (9 [33.3%] of 27 patients vs 20 [64.5%] of 31 patients; P=.030). In multivariate logistic regression analysis, as-needed opioid administration was negatively associated with 24-hour survival.

CONCLUSIONS

Opioid administration within 24hours before cardiac arrest per se was not associated with adverse outcomes. However, administration of opioid analgesics on an as-needed basis was associated with poorer survival outcomes than regular dosing. Greater attention should be paid to patients who receive as-needed opioid administration in the general ward.

Missed opportunities?: an evaluation of potentially preventable poisoning deaths

INTRODUCTION

Although most poisoning deaths are not preventable with current medical technology, in some cases different management decisions may have prevented fatal outcomes.

OBJECTIVE

This study aims to review reported poisoning-related deaths for preventability to provide insight to improve future care.

METHODS

Fatality abstracts published in the US National Poison Data System (NPDS) Annual Reports (2008-2012) were analyzed. Preventability was graded using a Likert scale of 1 (definitely non-preventable) to 6 (definitely preventable). Two medical toxicologists screened all cases. Cases deemed definitely not preventable (score 1) by both reviewers were excluded from further review and considered to be "non-preventable". All cases considered at least possibly preventable by either screener were reviewed by a multidisciplinary panel of 5 physicians for preventability scoring. Differences were resolved by consensus. Cases determined to be "preventable" (scores 4-6) were characterized by type of improvement issue involved (diagnosis, treatment, monitoring, other) and recurring scenarios.

RESULTS

Of 390 published abstracts, 78 (20.0%) deaths were considered at least possibly preventable by at least one screener. Of these, 34 (8.7%) deaths were determined to be "preventable" by the panel. Inter-observer agreement by weighted kappa analysis was 0.58 for screening, 0.24 for preventability, and 0.44 for specific aspects of care. The most common toxicants were salicylates (n = 9), opioids (n = 4), toxic alcohols (n = 3), fluoride containing product (n = 3), and bupropion (n = 3). The most common improvement opportunities involved treatment and monitoring.

DISCUSSION

Most of the ingested substances in preventable deaths have delayed GI absorption or require metabolic activation to produce a delayed effect (such as salicylates, opioids, and toxic alcohols), and therefore provide an opportunity for early recognition and successful interventions. Most improvement opportunities are clearly described in the literature but may be not recognized.

CONCLUSIONS

Based on an analysis of published NPDS data, a considerable number of poisoning-related deaths reaching medical attention may be preventable. The most common scenarios involved in potentially preventable poisoning fatalities related to monitoring and treatment. Salicylates and opioids were the most common agents involved in preventable deaths.

Flumazenil, naloxone and the 'coma cocktail'

Flumazenil and naloxone are considered to be pharmacologically ideal antidotes. By competitive binding at the molecular target receptors, they are highly specific antagonists of two important drug classes, the benzodiazepines and opioids, respectively. Both antidotes enjoy rapid onset and short duration after parenteral administration, are easily titrated and are essentially devoid of agonist effects. Yet only naloxone is widely used as a component of the 'coma cocktail', a sequence of empirical treatments to correct altered mental status, while experts discourage the use of flumazenil for such patients. This review contrasts the history, indications, published evidence and novel applications for each antidote in order to explain this disparity in the clinical use of these 'ideal' antidotes.

Harm reduction for young people who use prescription opioids extra-medically: Obstacles and opportunities

Extra-medical prescription opioid (EMPO) use - intentional use without a prescription or outside of prescribed parameters - is a public health crisis in the United States and around the world. Epidemiological evidence suggests that the prevalence of EMPO use and adverse sequelae, including opioid overdose and hepatitis C infection, are elevated among people aged 18-25. Despite these preventable health risks, many harm reduction interventions are underutilized by, or inaccessible to, EMPO-using youth. In this commentary, we describe key harm reduction strategies for young people who use prescription opioids. We examine individual, social, and policy-level barriers to the implementation of evidence-based approaches that address EMPO use and related harms among young people. We highlight the need for expanded services and new interventions to engage this diverse and heterogeneous at-risk population. A combination of medical, social, and structural harm reduction interventions are recommended. Furthermore, research to inform strategies that mitigate particularly high-risk practices (e.g., polysubstance use) is warranted. Finally, we discuss how the meaningful involvement of youth in the implementation of harm reduction strategies is a critical component of the public health response to the prescription opioid epidemic.

Internal medicine resident knowledge, attitudes, and barriers to naloxone prescription in hospital and clinic settings

BACKGROUND

The United States is facing an epidemic of opioid use and misuse leading to historically high rates of overdose. Community-based overdose education and naloxone distribution has effectively trained lay bystanders to recognize signs of overdose and administer naloxone for reversal. There has been a movement to encourage physicians to prescribe naloxone to all patients at risk of overdose; however, the rate of physician prescribing remains low. This study aims to describe resident knowledge of overdose risk assessment, naloxone prescribing practices, attitudes related to naloxone, and barriers to overdose prevention and naloxone prescription.

METHODS

The HOPE (Hospital-based Overdose Prevention and Education) Initiative is an educational campaign to teach internal medicine residents to assess overdose risk, provide risk reduction counseling, and prescribe naloxone. As part of a needs assessment, internal medicine residents at an academic medical center in Baltimore, Maryland, were surveyed in 2015. Data were collected anonymously using Qualtrics.

RESULTS

Ninety-seven residents participated. Residents were overwhelmingly aware of naloxone (80%) and endorsed a willingness to prescribe (90%). Yet despite a high proportion of residents reporting patients in their panels at increased overdose risk (79%), few had prescribed naloxone (15%). Residents were willing to discuss overdose prevention strategies, although only a minority reported doing so (47%). The most common barriers to naloxone prescribing were related to knowledge gaps in how to prescribe and how to assess risk of overdose and identify candidates for naloxone (52% reporting low confidence in ability to identify patients who are at risk).

CONCLUSIONS

Medicine residents are aware of naloxone and willing to prescribe it to at-risk patients. Due to decreased applied knowledge and limited self-efficacy, few residents have prescribed naloxone in the past. In order to improve rates of physician prescribing, initiatives must help physicians better assess risk of overdose and improve prescribing self-efficacy.

Glial dysfunction and persistent neuropathic postsurgical pain

BACKGROUND

Acute pain in response to injury is an important mechanism that serves to protect living beings from harm. However, persistent pain remaining long after the injury has healed serves no useful purpose and is a disabling condition. Persistent postsurgical pain, which is pain that lasts more than 3 months after surgery, affects 10-50% of patients undergoing elective surgery. Many of these patients are affected by neuropathic pain which is characterised as a pain caused by lesion or disease in the somatosensory nervous system. When established, this type of pain is difficult to treat and new approaches for prevention and treatment are needed. A possible contributing mechanism for the transition from acute physiological pain to persistent pain involves low-grade inflammation in the central nervous system (CNS), glial dysfunction and subsequently an imbalance in the neuron-glial interaction that causes enhanced and prolonged pain transmission.

AIM

This topical review aims to highlight the contribution that inflammatory activated glial cell dysfunction may have for the development of persistent pain.

METHOD

Relevant literature was searched for in PubMed.

RESULTS

Immediately after an injury to a nerve ending in the periphery such as in surgery, the inflammatory cascade is activated and immunocompetent cells migrate to the site of injury. Macrophages infiltrate the injured nerve and cause an inflammatory reaction in the nerve cell. This reaction leads to microglia activation in the central nervous system and the release of pro-inflammatory cytokines that activate and alter astrocyte function. Once the astrocytes and microglia have become activated, they participate in the development, spread, and potentiation of low-grade neuroinflammation. The inflammatory activated glial cells exhibit cellular changes, and their communication to each other and to neurons is altered. This renders neurons more excitable and pain transmission is enhanced and prolonged. Astrocyte dysfunction can be experimentally restored using the combined actions of a μ-opioid receptor agonist, a μ-opioid receptor antagonist, and an anti-epileptic agent. To find these agents we searched the literature for substances with possible anti-inflammatory properties that are usually used for other purposes in medicine. Inflammatory induced glial cell dysfunction is restorable in vitro by a combination of endomorphine-1, ultralow doses of naloxone and levetiracetam. Restoring inflammatory-activated glial cells, thereby restoring astrocyte-neuron interaction has the potential to affect pain transmission in neurons.

CONCLUSION

Surgery causes inflammation at the site of injury. Peripheral nerve injury can cause low-grade inflammation in the CNS known as neuroinflammation. Low-grade neuroinflammation can cause an imbalance in the glial-neuron interaction and communication. This renders neurons more excitable and pain transmission is enhanced and prolonged. Astrocytic dysfunction can be restored in vitro by a combination of endomorphin-1, ultralow doses of naloxone and levetiracetam. This restoration is essential for the interaction between astrocytes and neurons and hence also for modulation of synaptic pain transmission.

IMPLICATIONS

Larger studies in clinical settings are needed before these findings can be applied in a clinical context. Potentially, by targeting inflammatory activated glial cells and not only neurons, a new arena for development of pharmacological agents for persistent pain is opened.

From unwitnessed fatality to witnessed rescue: Pharmacologic intervention in sudden unexpected death in epilepsy

The mechanisms of sudden unexpected death in epilepsy (SUDEP) have been difficult to define, as most cases occur unwitnessed, and physiologic recordings have been obtained in only a handful of cases. However, recent data obtained from human cases and experimental studies in animal models have brought us closer to identifying potential mechanisms. Theories of SUDEP should be able to explain how a seizure starting in the forebrain can sometimes lead to changes in brainstem cardiorespiratory control mechanisms. Herein we focus on three major themes of work on the causes of SUDEP. First, evidence is reviewed identifying postictal hypoventilation as a major contributor to the cause of death. Second, data are discussed that brainstem serotonin and adenosine pathways may be involved, as well as how they may contribute. Finally, parallels are drawn between SIDS and SUDEP, and we highlight similarities pointing to the possibility of shared pathophysiology involving combined failure of respiratory and cardiovascular control mechanisms. Knowledge about the causes of SUDEP may lead to potential pharmacologic approaches for prevention. We end by describing how translation of this work may result in future applications to clinical care.

The opioid abuse and misuse epidemic: implications for pharmacists in hospitals and health systems

PURPOSE

The current epidemic of prescription opioid abuse and misuse in the United States is discussed, with an emphasis on the pharmacist's role in ensuring safe and effective opioid use.

SUMMARY

U.S. sales of prescription opioids increased fourfold from 1999 to 2010, with an alarming rise in deaths and emergency department visits associated with the use of fentanyl, hydrocodone, oxycodone, and other opioid medications. Signs and symptoms of opioid toxicity may include altered mental status, hypoventilation, decreased bowel motility, central nervous system and respiratory depression, peripheral vasodilation, pulmonary edema, hypotension, bradycardia, and seizures. In patients receiving long-term opioid therapy for chronic pain, urine drug testing is an important tool for monitoring and assessment of therapy; knowledge of opioid metabolic pathways and assay limitations is essential for appropriate use and interpretation of screening and confirmatory tests. In recent years, there has been an increase in federal enforcement actions against pharmacies and prescription drug wholesalers involved in improper opioid distribution, as well as increased reliance on state-level prescription drug monitoring programs to track patterns of opioid use and improper sales. Pharmacies are urged to implement or promote appropriate guidelines on opioid therapy, including the use of pain management agreement plans; policies to ensure adequate oversight of opioid prescribing, dispensing, and waste disposal; and educational initiatives targeting patients as well as hospital and pharmacy staff.

CONCLUSION

Pharmacists in hospitals and health systems can play a key role in recognizing the various forms of opioid toxicity and in preventing inappropriate prescribing and diversion of opioids.

Overdose Education and Naloxone for Patients Prescribed Opioids in Primary Care: A Qualitative Study of Primary Care Staff

BACKGROUND

The rate of fatal unintentional pharmaceutical opioid poisonings has increased substantially since the late 1990s. Naloxone is an effective opioid antidote that can be prescribed to patients for bystander use in the event of an overdose. Primary care clinics represent settings in which large populations of patients prescribed opioids could be reached for overdose education and naloxone prescription.

OBJECTIVE

Our aim was to investigate the knowledge, attitudes and beliefs about overdose education and naloxone prescription among clinical staff in primary care.

DESIGN

This was a qualitative study using focus groups to elucidate both clinic-level and provider-level barriers and facilitators.

SETTING

Ten primary care internal medicine, family medicine and infectious disease/HIV practices in three large Colorado health systems.

METHODS

A focus group guide was developed based on behavioral theory. Focus group transcripts were coded for manifest and latent meaning, and analyzed for themes using a recursive approach that included inductive and deductive analysis.

RESULTS

Themes emerged in four content areas related to overdose education and naloxone prescription: knowledge, barriers, benefits and facilitators. Clinical staff (N = 56) demonstrated substantial knowledge gaps about naloxone and its use in outpatient settings. They expressed uncertainty about who to prescribe naloxone to, and identified a range of logistical barriers to its use in practice. Staff also described fears about offending patients and concerns about increased risk behaviors in patients prescribed naloxone. When considering naloxone, some providers reflected critically and with discomfort on their own opioid prescribing. These barriers were balanced by beliefs that prescribing naloxone could prevent death and result in safer opioid use behaviors.

LIMITATIONS

Findings from these qualitative focus groups may not be generalizable to other settings.

CONCLUSION

In addition to evidence gaps, logistical and attitudinal barriers will need to be addressed to enhance uptake of overdose education and naloxone prescription for patients prescribed opioids for pain.

Predictors of Delayed Postoperative Respiratory Depression Assessed from Naloxone Administration

BACKGROUND

The aim of this study was to identify patient and procedural characteristics associated with postoperative respiratory depression or sedation requiring naloxone intervention.

METHODS

We identified patients who received naloxone to reverse opioid-induced respiratory depression or sedation within 48 hours after discharge from anesthetic care (transfer from the postanesthesia care unit or transfer from the operating room to postoperative areas) between July 1, 2008, and June 30, 2010. Patients were matched to 2 control subjects based on age, sex, and exact type of procedure performed during the same year. A chart review was performed to identify patient, anesthetic, and surgical factors that may be associated with risk for intervention requiring naloxone. In addition, we identified all patients who developed adverse respiratory events (hypoventilation, apnea, oxyhemoglobin desaturation, pain/sedation mismatch) during phase 1 anesthesia recovery. We performed conditional logistic regression taking into account the 1:2 matched set case-control study design to assess patient and procedural characteristics associated with naloxone use.

RESULTS

We identified 134 naloxone administrations, 58% within 12 hours of discharge from anesthesia care, with an incidence of 1.6 per 1000 (95% confidence interval [CI], 1.3-1.9) anesthetics. The presence of obstructive sleep apnea (odds ratio [OR] = 2.45; 95% CI, 1.27-4.66; P = 0.008) and diagnosis of an adverse respiratory event in the postanesthesia recovery room (OR = 5.11; 95% CI, 2.32-11.27; P < 0.001) were associated with an increased risk for requiring naloxone to treat respiratory depression or sedation after discharge from anesthesia care. After discharge from anesthesia care, patients administered naloxone used a greater median dose of opioids (10 [interquartile range, 0-47.1] vs 5 [0-24.8] IV morphine equivalents, P = 0.020) and more medications with sedating side effects (n = 41 [31%] vs 24 [9%]; P < 0.001).

CONCLUSIONS

Obstructive sleep apnea and adverse respiratory events in the recovery room are harbingers of increased risk for respiratory depression or sedation requiring naloxone after discharge from anesthesia care. Also, patients administered naloxone received more opioids and other sedating medications after discharge from anesthetic care. Our findings suggest that these patients may benefit from more careful monitoring after being discharged from anesthesia care.

Effects of remifentanil on esophageal motility: a double-blind, randomized, cross-over study in healthy volunteers

BACKGROUND

Recent studies have shown that remifentanil increases the risk of aspiration and induces subjective swallowing difficulties. The mechanisms are not completely understood. Here, we investigated whether remifentanil impairs esophageal motility and hypothesized that this is one possible underlying mechanism. Naloxone was used to evaluate whether the effects of remifentanil are mediated through opioid receptors. We also examined subjective swallowing difficulties and the influence of metoclopramide on remifentanil-induced effects.

METHODS

Fourteen healthy volunteers participated in a double-blind, randomized, cross-over trial at the University Hospital in Örebro, Sweden. They were studied on two different occasions, during which they were randomly assigned to receive either naloxone given as a bolus of 6 μg/kg followed by an infusion of 0.1 μg/kg/min, or saline 5 min before target-controlled infusions of remifentanil at three target-site concentrations: 1, 2, and 3 ng/ml. On both occasions, 0.2 mg/kg metoclopramide was given before the final measurement. Five swallows were performed during each measuring condition, and the metrics defining esophageal motility were measured by high-resolution manometry. Outcomes were differences in the metrics at baseline vs. during remifentanil infusion, with naloxone vs. placebo, and with remifentanil before and after metoclopramide administration. Differences in swallowing difficulties were also recorded.

RESULTS

Remifentanil decreased swallow-evoked esophagogastric junction relaxation and the latency time of esophageal peristalsis. There were no significant effects of naloxone or metoclopramide on remifentanil-induced effects, and we detected no differences in swallowing difficulties.

CONCLUSIONS

Remifentanil induces dysfunction of esophageal motility; this may contribute to the elevated risk of regurgitation and aspiration.

Use of Naloxone by Emergency Medical Services during Opioid Drug Overdose Resuscitation Efforts

Naloxone administration is an important component of resuscitation attempts by emergency medical services (EMS) for opioid drug overdoses. However, EMS providers must first recognize the possibility of opioid overdose in clinical encounters. As part of a public health response to an outbreak of opioid overdoses in Rhode Island, we examined missed opportunities for naloxone administration and factors potentially influencing EMS providers' decision to administer naloxone. We reviewed medical examiner files on all individuals who died of an opioid-related drug overdose in Rhode Island from January 1, 2012 through March 31, 2014, underwent attempted resuscitation by EMS providers, and had records available to assess for naloxone administration. We evaluated whether these individuals received naloxone as part of their resuscitation efforts and compared patient and scene characteristics of those who received naloxone to those who did not receive naloxone via chi-square, t-test, and logistic regression analyses. One hundred and twenty-four individuals who underwent attempted EMS resuscitation died due to opioid overdose. Naloxone was administered during EMS resuscitation attempts in 82 (66.1%) of cases. Females were nearly three-fold as likely not to receive naloxone as males (OR 2.9; 95% CI 1.2-7.0; p-value 0.02). Additionally, patients without signs of potential drug abuse also had a greater than three-fold odds of not receiving naloxone (OR 3.3; 95% CI 1.2-9.2; p-value 0.02). Older individuals, particularly those over age 50, were more likely not to receive naloxone than victims younger than age 30 (OR 4.8; 95% CI 1.3-17.4; p-value 0.02). Women, older individuals, and those patients without clear signs of illicit drug abuse, were less likely to receive naloxone in EMS resuscitation attempts. Heightened clinical suspicion for opioid overdose is important given the recent increase in overdoses among patients due to prescription opioids.

Reducing Fatal Opioid Overdose: Prevention, Treatment and Harm Reduction Strategies

The opioid overdose epidemic is a major threat to the public's health, resulting in the development and implementation of a variety of strategies to reduce fatal overdose. Many strategies are focused on primary prevention and increased access to effective treatment, although the past decade has seen an exponential increase in harm reduction initiatives. To maximize identification of opportunities for intervention, initiatives focusing on prevention, access to effective treatment, and harm reduction are examined independently, although considerable overlap exists. Particular attention is given to harm reduction approaches, as increased public and political will have facilitated widespread implementation of several initiatives, including increased distribution of naloxone and policy changes designed to increase bystander assistance during a witnessed overdose.